Becomes wise, full of ideas, says Roger? (4,3,7)

I believe the answer is:

gets the message

I'm a little stuck... Click here to teach me more about this clue!

'becomes wise full of ideas says roger?' is the definition.
I can't judge whether this definition defines the answer.

'becomes wise full of ideas says' is the wordplay.
'becomes' becomes 'gets' ('get' can be a synonym of 'become').
'wise' becomes 'sage' (similar in meaning).
'full of' is an insertion indicator.
'ideas says' becomes 'themes' (I can't explain this - if you can you should give a lot more credence to this answer).
'gets'+'sage'='getssage'
'getssage' enclosing 'themes' is 'GETS THE MESSAGE'.

Can you help me to learn more?

I've seen this clue in The Times and The Sunday Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.